Micrometer-caliper.



J. BATH.

MICROMETER CAMPER.

APPLICATION HLED SEPT. 8, 1914. v 1,202,019. Patented ont. 24,1916.

2 SHEETS-SHEET I.

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MM 127W 1. BATH.

MICROMETER CALIPER.

APPLICATION FILED SEPT. 8, 1914.

1,202,019. patent@ 001.211,1916.

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JOI-IN BATH, OF WORCESTER, MASSACHUSETTS, .ASSIGNOR TO JOHN BATH &COMPANY, INCORPORATED, OF WORCESTER, MASSACHUSETTS, A CORPORATON OFMASSACHU'# SETTS.

MICROMETERf-CALIPER.

reoaoie.

To all iii/om t may concern.' i

Be it known that I, Jol-1N BATH, a citi- .zen of the United Sta-tes, andresident of lvorcester, in the county of l/Vorcester and State` ofMassachusetts, have invented cer-` tain new and useful Improvements 1nMi ci'ometer-Galipers, of which the following is .y a specification.

ance, and in which there is an indicator opcrated thereby to show atonce the dimension or the difference from a given dimension of the thingwhich acts upon the caliper points or jaws.

.The general object of the invention is to provide an instrument orcaliper of the sort indicated which shall be capable of measuring thedimensions of Aan article, whethei the same is stationary or isrevolving in or with the work holder of a machine tool, and to detectand indicate the amount of eccenti'icity or other error in a piecehaving a curved or a plane surface.

Y More specifically my Objectis to embody in an instrument ofthecharacter indicated having the capacitv for operation as indicatedabove, the features of construction'and arrangement ofthe severaloperating parts by which errors in the operation of the in-. strumentare eliminated and the dimensions` and distances measured by theinstrument may be manv times multiplied at the indicating point withextreme accuracy.

In vcarrying the foregoing objects into practical effect I have producedan instrument of whichvario-us forms and embodiments are illustrated inthe accompanying drawings, 'to which reference is made in connectionwith the following descriptionV for a complete and detailed explanationof the principles of my invention and a possible inode of application ofsuch principles in an operative device.

Referring to the drawings, Figure 1 repl.resents a nlan view of aninstrument ,eni-l speeiecation 0f Letters Paten-e. Patnfwd Oct- 24,,1916,

l Application filed September 8, 1914. Serial No. 860,540. i I

bodying my invention. Fig. 2 is a vertical sectional view of theinstrument taken on line 2 2 of Fig. 1. ofthe instrument as seen. fromthe left of Figs. l and 2. rvFig. i'jis a sectional view of :i detail ofthe instrument taken on linev VL1--4 of FiggQ. Fig. 5 is anotherdetail-sectional view taken on line 5-5 of Fig. 2. Figli is anothersectional detail view taken on line 6-6 of Fig.2. Fig. 7 is a sectionaldetail view taken on line 7 7 of Fig. 2. Fig. 8 is a plan view of oneofthe movable caliperingpoints oinjaws of the instrument shown inconnection with the adjacent part ofthe frame of the instrument. Fig. 9is a side elevation of a modified 'form ofthe instrument embodyingthesame principles as that shown in theprevious figures but containingvcertain alterations andadditions in its construction, said Fig. 9representing the instrument with one of the faces of its inclosingcasingrem'oved. Fig. Y10 is an elevation partly in section on anenlarged scale of a detail of the instrument shown in Fig. 9. Fig. 11 isan elevation of the mechanism shown Vin Fig. 10 as viewed from the rightof said figure. Fig. 12 is a sectional view on line ,12-12 of Fig. 10.Figs. 13, 141, vand 15 are views showing on a smaller scale the externalappearance ofan embodiment of the instrument substantially identicalwith that shownin Figs. 1 and 2 lacking certain of Ythe details ofsuchuform of the instrument, Fig. 13 being a plan view and Figs. 14 and.15 elevations of'opposite faces, respectively, 'of such instrument. Fig.16 is a sectional view on line lf3-16 of Fig. 14.

The same reference characters indicate thesame parts in alltlie figures.

Referring first to Figs. 1 to 8 inclusive, which show in complete detaila practical and desirable embodiment of my invention, 1 representstlieframe or body Vof the caliper instrument, which frame or bodyissubstantially U-shaped having arms 2 and 3 extending 1n approximatelythe saine-direction and separated by a lspace of sufiicentwidth toreceive the article `to be measured. A porJY Fig. 3 is an end view tionofthe frame or body 1 is recessed to form a chamber 4 in which themoving parts or mechanism which transmit motion to the indicatingelement are located. This chamber is normally closed by a detachablecover plate 5 (shown in Fig. 1) which is attached to the body by screws6 and conformsat its edges to the outline of such body. Between thebodyand the cover at the edge or side which, for the purpose of descriptionmay be called the top side or edge is left a slot 7 through whichprojects the end `of an arm 8 carrying an indicator or pointer 9 whichacts in connection with a scale 10 when moved by the calipering pointsor jaws as hereinafter described. The arm 2 has a passage in which iscontained a bar or rod 11, the latterl constituting one of the memberswhich may be called for convenience of description the caliperingabutments or points of the instrument. The said abutment 11 is shownconveniently as a rod which is adjustable endwise in the passage in thearm 2, and which is provided with graduations 12`for indicating inconnection with an in-f dex or guide on the armf2, the position ofj*adjustment of said abutment. The arm 2 is formed with a slot 13 leadingfrom its outer endinto the passage containing the bar 11, andthe-earsformed by such slot are pulled together by a screw 14 to clampthe abut- Any desired form of caliper abutment may be used in place ofthe bar 11, with any desired means for adjusting it, or if desired,without provision for any adjustment whatever. My invention is concernedparticulai-ly with other features of the instrument;

l abutments.

from the thrust rod to the arm 21 of lever ment bar 11 and secure theadjustments thereof.

28 and has an arm 29 connected by a pivot to a link 31, which in turn isjoined by a pivot stud 32 with the short arm 33 of a bell crank leverpivoted at 34, the long arm of said bell crank lever being the arm 8,previously described, which carries the index or pointer 9. All thelevers, links, and pivots above described are 'contained within theforcetending to cause displacement is removed.

When an article to be measured is passed between the abutments 11 and15, as shown by the broken circle 37 in Fig. 1, it shifts the abutment15, if its diameter or thickness is greater than the distance betweensaid Pressure is then transmitted 19, depressing the short arm 21 andraising the long arm of said lever, thereby raising the link 25,lever27, link 31 and lever arm l, and swinging the index arm 8 and findex 9 from right to left across the graduations and figures of thescale 10. The extreme' limit of movement of the various parts isindicated by the positions of such irts shown by the dotted lines inFig. 1. By comparing the distance between the full and dotted linepositions of the abutment 15 than the abutment 11, and provided thereis'l-jwith the distance between the coresponding some element answeringthe purposes and serving the functions of the abutment 11, it isimmaterial how such abutment is formed or arranged and whether or not itis adjustable. Any of the adjustable caliper jaws used at the presenttime in micrometer calipers, and any of the mechanisms and means foradjusting the same may be substituted for the bar 11 and the means foradjusting the same here shown. The caliper abutment or jaw 15complemental to the abutment l1 extends toward the latter from the arm 3of the body, being carried by lever 16 pivoted to a stud 17, the entirelever except the projecting abutment 15 and a short arm 18, presently tobe described, being contained within the arm 3 of the frame. A secondlever 19 is pivoted to a stud 20 and is formed with a short arm 21 whichbears againstone end of a thrust rod 22, the opposite end of whichpresses against a. portion ofthe abutment 15. The long arm of lever 19is jointed by a pivot'24 to a link 25 which is connected by pivot 26 toa lever 27. Said lever 27 is "pivoted on a pivot stud positions of theindex arm, it will be seen that the movement of the caliper abutment ismany times multiplied at the indicating point. In the instrumentdesigned as here illustrated the multiplication is approximately onehundred times.

I haveprovided an adjustable stop 38 to limit the movement of returnfrom the displaced position of the indicating linkage. Said stop isconveniently screw threaded through a wall of the casing into proximitywith the lon arm of lever 19, and having an external head 39 foractuation by the thumb and fingers of the user. Another stop 40 for thesame purpose and being of substantially the same type and constructionis provided to act in connection with the lever 27, being arrangedadjacent to an arm41 of said lever which projects downwardly from thepivot or fulcrum 28. Said arm 41 cai'- ri es a stud 42 which projectsthrough a. slot 43 in the side of the casing or frame and is providedwith a clamping screw 44, (F ig. 7) which is employed for clamping thelever Whenever it is desired to prevent movement of theindex. vEitherstop 39.01' iOisuseful for first setting the tindex yatthepoint on the yscale xwhich shows the Ysize to ,which -a piece ofwvorlr is..to Vbebroughtby having' material removed trom its surface. Aslong' Aas thearticle remains ofi larger slze than the desired.y dimension, it movesthe index Whenever placed. between the. caliper. Aabutments, thus`affording a `tpialitative means `for indicatingfthecexcess of itsdimension overthe required dimension, .and -the approximate `amount ofsuch excess, ina much., more rapid Way. than vWould bepossibleifit'Werernecsk essary :for Athe Workman, each' time :he

measured the `Work, tosearch for thev graduation Vrepresenting the finalsize and determine Whether the graduation beside the index when .thecaliper is engaged. .with the .Work is of greater .value thanv'therequired size.

Thatis, the` stops 38 and 40eme. means *for amount of eccentricity, Yorrdeviation from a f plane, respectively, of=the surface-ofsuch piece. A"deviation from absolute truth ofV anypoint offsuch surface `Willdisplace theprojection 4.5, and byacting through the linkage Y mechanismalready described, 'dis- V place the index 9. -i-.similar service isperformed by la pointed projectionAS- which is connected to .an arm49oftheilever 27 land may be used as ta. surfacegage.

This instrument Vis V.adaptedV to Vbe. used either as ahand: tool crasanattachment on a machine tool. For the s purpose .f ofptheY latter use itis provided with a stud 15,0 (Figs, 13.and-14)..on one sideof'the'frame, whichforms th'e pivot orswivel for a.. shank or bar-51which is .adaptedtoi be .secured in f the tool post orsome other.convenient part of Aal ymachine tool, whereby.; the caliper can beIadjusted at'the properlocation and may be moved tobringits measuringabutments .over the Work in. theu machine.

I .WilLnow-refer tof'features ofthe instru-V ment which give it thequalityot` eXtreme accuracy which is. desirable forza practicalmicrometer instrument. rln the lirst place the .caliper abutment 15 Yislocated at sol great a distance Vl'romthepivot :'17 ofv the lever by.Which it is carried, that thelmovement of. any point on theycontactsurface of said vabutment.Within.the.short-path to whichits.movement..islimited is sonearly in a. straight line that the'deviation of such path `roma straight line isincapableof measurement,Wherefore: it maybe .said that to all vintents and purposes the abutment.15

moves in .a straight line towardandffrom 17 and f2.0 are parallel' to.each other.

condition `above v.described `may be stated in .anotherfvway by sayingkthat the-range the .abutment c :11.- 'Again 'fthe abutment 15 u projectsfrom l the 1i frame z arml .a ,suHicient distance to permit .of-jthepractical! .use oi y theiinstrumenand theslever 1.6 is.curved ablethefulcrum 17 to be. placed inafcer# tain definite position, aspresentlydescribed; Another :.featurel resides' in; the position Sand' larrangement lof 'the .thrust rod 22. 1 Y,Thisv rod isccontainedinterchangeably in feither.4

of Vtwo. or ymore-recesses `52 'inthe under. sidey of thefabutment :15,and sockets. Aor notches 53.2in'the'leverarm 2L '.The ends.. of thethrust .rod-lare preferably formed* -Withf i pointed. or.yknifezedgedbearings against the :sa v abutment and lever arm,respectively, .al-vy though they 'fm ay be a :otherwise formed,v as Ywith rounded ends, Without` departinglffrom thewspiritof the invention.1F or example,

theA vuppeiaend .of the rodywhich.*isacte'd on".

by. -thelabutment,. may :"be' rounded, rior. this en'd; of; the rodhaspracticallyf. no displace? f i bears. onthe. shortosciilating leverarm 21;?. t

long..as .possibl`e, and :therefore vits upper end?` is.y seated.y.close-tothe outer.` limit. of. thel abutmenty 15, .sof thatithere will.be no.. appre-V ciable i-change 1 in. theidirection of :the f vrody andof the line of tl1rust;.-thereof.-onthe v lever arm 21fdue. to suchyslightrdivergence aseXists.between-:theaarc of movement .of the bearingpoint, .on sucharm .andthe tangent to such. arc. :Then thelfulcrums17and;

thel-fulcrum 2.0,.aregso located with respect to'the-rodg22that alinefromthe centery of fulc-rumf17fthreughf the mi'ddlepoint in the traveloftheicenterfof curvature orthe'up.-`

per eHdOuthe rod. 22 (croi:l thefbearing pointofrsuch .end when the.lbearing isa kniferedgeor pointedjbearing) .is ,exactly perpen'dicularLto lthe midfposition of :the rod. .Similarly la, line drawn-tromy thecen'- ter of theffulcrmn .'20 through. the. midA point ini the movement.off the lower.; bearing. endv ofthe thrust. rod. (or. `of thel center.of .curvature ofsuch end Whenthe latter islspherically or.cylindricallycurved), kis perpen-'f dicularV to. the rod. The linesthus described. as .drawnfromzthe centers. of the fulcrums Theotmovement of the contact points of the r rod 22 `on.A the. abutmentl'and :on: the lever arm 21respectively, (or of thexcentersy oitycurvature lof thegbearing -.oiisuch rods, When such-bearings are curvedsurfaces) extends.`

equal distances toopposite sidesyoflines V perpendicular lto'.V such rodand. passing through 'the pivotal centers k17 yand 2,0 o1`vgtheabfutments 15a-nd; the leverarm 2l,.re speCtVely.; ;'It,shou`1cl beherenoted the, center of curvature fof therounded bearing end'.

of the `rod'isfequivalent to a.` knife edge or point bearing,being the.pontfwhich does not change its location with respect to theadjacentengagedmember in consequence of al .swinging` movement *of therodi; .Conse-. quently-the lterm engaging point orVv bearingpoint'.mayf.beu`sed to include bothv apoint orllne bearing, andthe center of.

`curvature of thefround'ed bearing, of the rod, inthis speciiication.-:Similar condi-,

V; tions "i obtain withrespecttothe lever .27,

lever 33, link 31 and link 25. vThe lever' 27,V

turns through equal angles to either side .of

.fa 'linea-.w drawn throughfits axis oiioscil-` Vlation, and lever 33correspondinglyturns .through `equal angles' to eitherside of aline & 5"drawn :through its axis..L These lines and represent, respectively.the: "middle 'posiand b-h Bythis vconstruction and arrangement I secure'the maximum possible.

accuracy in, an instrument wherethe jmultii plying mechanismf consistsof'levers,Avv and I secure such great accuracy that noerror can b4detected l even @by the most" .delicate in- The instrument maybe.altered4 as to the multiplica-tion of its reading byshiting the thrustrod122xrom' onefof-,the sockets 52 and notches 53ltothe other.

, "as; the. other,` whereby shiftingv the: rod

`from the firstlnotch to th'ei second doubles the ,multiplicationofmovement-of the index.,-Th`e bottoms 'of both notches 53 are on ythesame lineextending from. the center of the "stud 20. perpendicular to fthe rod. 22

^ when the lever `arm'21 is in its ymid-position.y

An additional featurevapplicable to the instrument abovefdescribedisshown in Fig. 9,'where 11 and `15` represent. the same'calipering ormeasuring abutments herein before describedfand-M,55, and 56, 57represent additional pairs of,v complemental' caliperwabutments, onemember of' each said additional pairsbeingsecured, to'or carried bythesame 1lever 16, which` carries the 'abutment 15. The complementalabutments are fally fixed in4 the armf2l ofthe .instrument Mframe@ Thevarbutments 57, 55, V:andi -15 arev at progressively diminishing'distances from the complemental `abutments 56, 54, and 11,

f 0' respectively, vwhereby veach pair "of complemental abutmentsmay beused in .succession for\ rneasurmg` a dimension of the Work which 1sbeing reduced. Thus the. .instrument may be used for measuring workwhich" ismuch larger. than therequiredfinalsize Vwithout requiring the'caliper abutmentsv to, v

l One of the.v notches 531is twice as arfromthe ulcrum.y

have an lexcessive range of movement, or re-l quiring the graduations ofthe scale to be too fine, or requiring any adjustment of the abutmentcomplemental to the one which` actuates the index.` Fig. 9 also showsavmodication in the multiplying linkage, although itis to be understoodthat such modiiication is not. of necessity used with the plurality ofabutments corresponding to 54, 55, and

` 56, 57, `forsuch abutments may be as well used with, an instrumenthaving a linkage mechanism shown in Fig. `1. The difference in theymultiplying vtransmission linkage shown` in Fig.- 9, consists in this,that the movement-:is transmitted directly from the lever 19 tolever 58,which carries the index arm 3, bymeans of a link 59 which is pivotallyjoined to the'end ofthe lever 19 and to the point 60. of thelever 58.Link 59 consists of a .rod which is oppositely threaded at its ends,"which ends are screwedlinto bearing blocks 60`and` 61 contained insockets in the levers 58 and 19, respectively, such blocksbeingpreferably cylindrical and arrangedwith their axes parallel to theaxes of the'levers. Conveniently by rotating the rod 59 the position ofthe index may be ad- Vjustedf..with respect to `the caliperadjustments@Y a 2 Wherever I `have used .the terms verti- CalY andhorizontal orfupper and doneso'wvith reference to the position of theinstrument shown in the drawings,lnot l1nte'ndin'g therebyto. imply anylimitation 1n the construction or arrangement of the parts or mode of"use ofthe instrument. i Y rfhe caliper made according to my inventionisuniform in its action, because the movement of` the measuring abutmentis resisted by Va long and flexible spring of uniform power, whereforethe accuracy of readings takenV does notdepend on the delicacy of touchof the workman. The instrument shows thereading instantly withoutnecessity of adjustment or manipulation of any part, whereby it. may beused to secure measurements-v with great rapidity. The` prin` ciplesofits construction, as hereinbefore described, secure greatf accuracy inresults.

What I claim and desire to secureby' LettersPatent is:

1. A micrometer caliper comprising a frame, a caliper abutment pivotallymount- Aed von said frame, an indicator, and transmission mechanism'between said abutment permittedfzto suchface' togioccur ina sub-QV,-

stantially straigh'tline, and T'the ends of the vthrust"rod beingengaged with the abutmenty and lever at points forming two ad;v

jacent angles .cfa rectangle of which the opposite sides pass .throughYthe pivot axes of said abutment and lever, respectively,

when f in l their mid positions.

2. A micrometer caliper comprising a body, ameasuring abutment, a iixedabutment,-a lever pivoted tosaid body carrying said measuringr abutment,Va motion# multiplying leverv pivotedjadjacent to A,said

abutment, the pivotal axis of said levers 'being parallel,-an indexoperated by said multiplying lever, anda thrust-rodiinter? posed betweenand in-fengagement with `said measuring abutment and said=multiply inglever, the-pivots of said levers beingv in planes 'perpendicular to theline between the fixed and' measuring abutments and k'separated kby adistance equal to fthe length of saidthrustrod. Y

'3.1 A 'micrometer :caliper comprising a body, 'fa-'measuring abutment,a lever pivoted tofs'aid body carrying said abutment, amotionfmultiplying leverl pivoted adjacent tok saidabutment, an indexoperated bysaid multiplying lever, and a thrust rod interposed betweenand'in engagement with said f abutment and said multiplying lever, the

pivots of said leversbeing so disposed. with respect tosaid thrust rodthat such rod is A approximately perpendicularto lines drawnrespectively from. the pivot of. the abutmentcarrying lever to theengaging point of' the rod with the abutment, andfrom the pivot of' themultiplying lever to the engag- 'ingpoint of the rodwitli said lever.

4, A micrometer caliper comprising a body, a measuring abutment, a leverpivoted Vto said body carrying saidy abutment, a motionmultiplyingleverrpivoted adjacent to said abutment, an index operated-by saidmultiplying'lever, anda thrust rod interposed'bev tween and inengagement with said abutment and said multiplying lever, the pivots ofsaid levers being so disposed". with respect to said thrustV rod thatwhen the abutment, rod, and multiplying lever are in the middle pointsof their permitted ranges of Vmove- `ment, the line joiningtheengagingpoints of the rod with the abutment and lever is perpendiculartolines joining said engaging points with the pivotalv axis of theabutment and pivotal axis of the multiplying lever,

` respectively. Y

5. ln amicrometer caliper, a measuring abutment pivotally mounted toswing on an arc of such longradius that the divergence of the movementof the abutment within the range of movement permitted, fromV astraightline isinap'preciable, a multiplying lever having a short armand a long arm andpivotally locatedat sucli a. pointthat its short armis adjacent to said abutment,

` at different said; frame, l ak Vmountedon said frame and movabletowardl said? abutnfientand. short lever arm. having bearingjpoints atdifferent distances'-romV fthe [tulo-rum of' the f lever, atransmissionYV .member7 adapted to. lbe engagedwith either setpofbearing points of the r`abutment.and

leverjwhereby to alter'the -multiplication of movementtransn'iittedto-the indicator, and a distance indicator connectedforoperation bythelongarmofsaid lever.l l

- 6. A micronieterr calipery f comprising va frame, a ,stationaryabutmentffcarried-by Y saidf-frame,g a .g complementall abutment mountedon said f frame and movableA ltoward v and awaycfromsaid stationaryabutment, ak

lever havingv a short armganda long; arm

pivotedito said frame, a transmissionjmem# ber extending between andAhaving: l affbearing `ons'aidmovable abutment and the 'short arm ofsaid lever respectively, afsecond lever lhavinga long armfanda sho-rtarm,Y transmission means between the longarm of the iirstxleverandvtlieshort arm ofthe second lever,;anda distance vindicator operated bytheflongv arm ofi-the second. lever, the saidV abutment and the shortarm of the rst frame,` stationary Aabutment carried-k byV complementalkabutment and away from said' stationary abutment, a

.lever having a shorty arm and a long .army piv'oted to said frame, atransmission member extending betw'eenfand having a bearing onsaid-movable abutment and the short arm of said'lever respectively,r asecond leverv having a long arm and a short arm, transmission meansvbetween the long arm f of the first lever and the short arm of thesecond lever, and a distance indicator operatedby the long arm of thesecond lever, said levers being so arranged that the short armskk of'both' are` parallel to one .another when at f tlie middle Ypoint. oftheir permitted franges of` movement'.

8. .A vmicrometer measurii'ig instrumenty comprising ay frame, anabutment mounted 1 movably upon-saidframe adapted to engage the articleto .-be measured, a motion-multiplying lever having aV short armarranged toA extend approximately perpendicular to the transmissionmemberbetween and Aengaged with; said abutment -and theV short arm ofsaid lever so .located .thaty the line `between its points ofengagementwith the lever and abutment` isapproximately perpendicular toythe-said lever arm, saidlever having also a long arm, a second leverhaving long andy Vshort arms, an'indicator connected for oper-'-Vdirectionof movement of said abutment, a. Y

Tationlby the-long ,arniof said secondlever,

an intermediate lever,ja link Vconnecting the vsaid Vintermediate leverwith thelong arm tot the vitirst"named lever; and asecoii'd linkconjnectingtheintermediate leverlwiththe short armv-otthe;,secnndlfnamedi lever,f theV said levers'beingfso arranged?thatwhen in their l lmiddleposition-theshort vrariigoi the'second lever ,-isparallelto the-arm of the -interme- "link is Vconnected diateleverfwith- `which fsaid, ysecond y named 39.1A mici"meterf `measuring!vinstrument "comprising-1 a frame,- an; abutment mounted movablyVuponl:saidiraine adapted to engage the varticle to kbe measured, aVuI''notion-multi y plying'lever having aishort armarranged to'extend lapproximately perpendicular Vto the direction of movement ofsaidabutment, a transmission member "between and rengaged with saidabutment and the short arm or' said lever so located that'the linebetween itspoints 'of engagement with the lever and abutment isapproximately? perpendicular to the said leverarm, said -lever havingalso a longarinj, a second flever havinglong and short arms, anindicatorjconnected Jor'oper-v `ation by the longarm` of rsaid secondlever,

' i, anintermediate lever,ja `link connecting the perpendicularito thesaid secondnamedlink. i A 110. In u micrometer caliperin '40,- and-adistance indicator,a motion-multiplysaid intermediate `leverwithi thelongjarm of fthe irstnamed lever, 'and a second link connecting theintermediate lever with the short of the second nainedle'verythe saidle-V vers `being so rarrangedthat when in their middle position" theshortarin of.V the second lever is parallel. tol the-arm ofthefintermediate lev`er^withV which :said""second named link "isconnectedrand both said arms are tion with-a Vmovable measuring abutmentY ing nmechanism. between said a `abi'itineifit and i said; indicatorV`comprising a Vlever .Y having faxlong arm with which said-indicator isconnected Iand having a vshort arm, aV link joined. towthe short 'armVof said lever, a second leveivgoinedto saidrlinl, said levers beingfarranged so as-to swing equal distances s to` opposite sidesotaMmid-position in which the said linlr is perpendicular to the arms off fboth levers `with which it is. connected, and

a 4third lever having4 a long arm connected jwitli the second` namedvlever and having ralsliort arm arranged adjacent tothe measuringabutment in positionf-to rbe movedl when the f abutment' is 'moved.

A. `11.f1na micrometerjcaliperin combination'g with a movable` measuringabutment andv a distance indicator,j a motion-multiplyingmechanismbetween said abutment and said indicator comprising al leverhaving a long arm with whichsaid'indicator is connected and haviiigashort arm, a link joined to the short arm ofsaid lever, a secondlevei'joined to said link, said levers being arcoinbinaranged "asfto swingequaldistances to oppositesidespof a mid-position in which thesaidllinlr isperpendicular to the arms/of both levers withV which it isconnected, a thirdy lever. having a long arm andaashort arm, a linkconnected with the second lever u andv with tlie'long arm ofthe thirdnamed lever and bein` arranged approximately parallel to the nrstnamedlinlr,` and said third lever being arranged with its shortarmadjacentto the abutment'and extendand said short arm.,

12. A micrometer caliper comprising va 4iframe having separated 'arms,measuring abutments extending their respective arms towardbne another,one or said abutments @being movable vtoward and fromv the otherandbeing pivotallv connected to the framev at such a distance vfrom theline of its move- Vment that the arc through which it swings issubstantially coincident at all points with `a straiglitiline tangent tosuch arc, a multiplying lever .pivoted on an axis parallel to that ofthe abutment nearv the abutment andhaving a short arm extending acrossthe prolongation of the line in which ,the Yacting face of the abutmentisrpermitted to movev and being approximately*perpendicu- Alar to saidline, a thrust rod engaged with v the abutment at a point close to theacting face thereoi` and also engaged with said short lever y'saidpoints ofiengagement being in the line of movement of the abutment andalso in lines perpendicular to said line or movement which pass throughthe pivots of the movable [abutment and of the multiplying leverrespectively, and said lever'fhaving along arm, andan indicator operatedby the long arm of said lever.

13. A micrometer caliper comprising a `iframe having separated arms,measuring 'abutments extending their respective arms yhaving va yshortarmy. extending across the prolongation ofthe line in which the actingface of the abutment is permitted to move and being approximatelyperpendicular to said line, a thrust -rod engaged with the abutment at apoint close to the acting face thereof Vand also engaged with said shortvlever arm, said points of engagement-being in the line of movement ofthe abutment, and said lever having a long arm, and an indicatoroperated" by the long arm or said 'fingperpendicularly vtogthe'lineofrmoveyment oftheabutment, and a transmission member interposedAbetween the abutment iio Vwhich said level` is moved by the normallever, and a stop mounted in the frame at In testimony whereof I haveaffixed my the side of the long arm of said lever from signature, 1npresence of two Witnesses.

displacements of the abutment, said stop be- JOHN BATH' ing adjustablein the plane of displacement Witnesses:

of said arm to limit the return of the arm HUBERT S. PARK,

from displaced position. f ARTHUR S. WASHBURN.

Copies of this patent may be obtained for ve cents each, by addressingthe "Commissioner of Patents, Washington, D. C.

